Optical device

ABSTRACT

An optical device ( 10 ) includes a joining structure in which a first conductive film ( 110 ) and a second conductive film ( 130 ) are joined to each other. The first conductive film ( 110 ) that constitutes the joining structure is constituted by a conductive material. The second conductive film ( 130 ) that constitutes the joining structure is constituted by a metal material. Apart of the second conductive film ( 130 ) comes into contact with the first conductive film ( 110 ). A plurality of concave portions are provided in a contact surface of the second conductive film ( 130 ) which comes into contact with the first conductive film ( 110 ). The contact surface has a surface roughness greater than a surface roughness of a non-contact surface of the second conductive film ( 130 ) which does not come into contact with the first conductive film ( 110 ).

TECHNICAL FIELD

The present invention relates to an optical device that uses an opticalelement such as a liquid crystal element and an organic EL(electroluminescence) element.

BACKGROUND ART

An optical device is used as various illuminating devices or displays.Generally, it is necessary for the optical device to have a joiningstructure that joins different materials such as terminals andinterconnections for transmission of an electrical signal that drivesthe optical element. For example, the organic EL element, which is anexample of an optical element, includes a transparent electrode, anotherelectrode that is disposed to face the transparent electrode, and anorganic layer that is interposed between the electrodes. As a technologyrelating to the organic EL element, for example, there are technologieswhich are described in Patent Document 1 and Patent Document 2.

In the technology described in Patent Document 1, an electrode formed ona light-emitting function layer and a lead-out electrode that supplies adisplay signal to the electrode are fused and joined. Specifically,Patent Document 1 discloses a configuration in which a negativeelectrode that is constituted by a metal electrode layer, and a metallead-out electrode layer are fused and joined at the connection portionthrough localized heating with laser light.

Patent Document 2 describes a light-emitting element including anelectrode that is constituted by a metal line that is formed in a linearshape, and a polymer line that covers an upper surface and a lateralsurface of the metal line.

RELATED DOCUMENT Patent Document

[Patent Document 1] Japanese Unexamined Patent Application PublicationNo. 2003-264064

[Patent Document 2] Japanese Unexamined Patent Application PublicationNo. 2006-93123

SUMMARY OF THE INVENTION

In the joining structure in which a first conductive film and a secondconductive film are joined to each other, high contact resistance mayoccur between the first conductive film and the second conductive film.In this case, connection reliability between the first conductive filmand the second conductive film deteriorates, and thus there is a concernthat power consumption of the optical device may increase.

As an example, a problem to be solved by the invention is to reducepower consumption of the optical device by improving the connectionreliability between two conductive films which are joined to each other.

According to the invention of claim 1, there is provided an opticaldevice including a joining structure in which a first conductive filmthat is constituted by a conductive material and a second conductivefilm that is constituted by a metal material are joined to each other.In the joining structure, apart of the second conductive film comes intocontact with the first conductive film, and a plurality of concaveportions are provided in a contact surface of the second conductive filmwhich comes into contact with the first conductive film.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, advantages and features of the presentinvention will be more apparent from the following description ofcertain preferred embodiments taken in conjunction with the accompanyingdrawings.

FIG. 1 is a plan view illustrating a light-emitting device according toa first embodiment.

FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1.

FIG. 3 is a cross-sectional view taken along line B-B in FIG. 1.

FIG. 4 is a view illustrating a part of the light-emitting deviceillustrated in FIG. 1.

FIG. 5 is a view illustrating a part of the light-emitting deviceillustrated in FIG. 1.

FIG. 6 is a view illustrating an example of a joining structure that isconstituted by a first conductive film and a second conductive film inthe first embodiment.

FIG. 7 is a view illustrating an example of a joining structure that isconstituted by a first conductive film and a second conductive film inthe first embodiment.

FIG. 8 is a view illustrating an example of a joining structure that isconstituted by a first conductive film and a second conductive film inthe first embodiment.

FIG. 9 is a plan view illustrating a light-emitting device according toa second embodiment.

FIG. 10 is a cross-sectional view taken along line C-C in FIG. 9.

FIG. 11 is a cross-sectional view taken along line D-D in FIG. 9.

FIG. 12 is a view illustrating a part of the light-emitting deviceillustrated in FIG. 9.

FIG. 13 is a plan view illustrating a configuration of a light-emittingdevice according to a third embodiment.

FIG. 14 is a cross-sectional view illustrating a configuration of anoptical device according to a fourth embodiment.

FIG. 15 is a plan view of an optical device.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the invention will be described withreference to the accompanying drawings. In all of the drawings, the samereference numerals will be given to the same constituent elements, anddescription thereof will be appropriately omitted.

First Embodiment

FIG. 1 is a plan view illustrating an optical device 10 according to afirst embodiment. FIG. 2 is a cross-sectional view taken along line A-Ain FIG. 1, and FIG. 3 is a cross-sectional view taken along line B-B inFIG. 1.

In addition, FIGS. 4 and 5 are views illustrating a part of the opticaldevice 10 illustrated in FIG. 1. In FIG. 4, particularly, a positionalrelationship between a first conductive film 110 and a second conductivefilm 130 is illustrated. In FIG. 5, particularly, a configuration of aninsulating layer 120 is illustrated. FIGS. 6 to 8 are views illustratingan example of a joining structure 200 that is constituted by the firstconductive film 110 and the second conductive film 130 in thisembodiment. In this embodiment, the optical device 10 is, for example, alight-emitting device such as an illuminating device and a display.Hereinafter, description will be given with the optical device 10 set asa light-emitting device 10.

In the joining structure 200, a first conductive film 110 that isconstituted by a conductive material and a second conductive film 130that is constituted by a metal material are joined to each other. A partof the second conductive film 130 comes into contact with the firstconductive film 110. A plurality of concave portions 204 are provided ina contact surface 206 of the second conductive film 130 which comes intocontact with the first conductive film 110.

In addition, the light-emitting device 10 according to this embodimentincludes the joining structure 200. The light-emitting device 10includes an organic EL element 20, a first interconnection 114 and alead-out interconnection 134. The organic EL element 20 includes a firstelectrode 112, a second electrode 152, and an organic layer 140 that isdisposed between the first electrode 112 and the second electrode 152.The first interconnection 114 is electrically connected to the firstelectrode 112, and is constituted by the first conductive film 110. Thelead-out interconnection 134 is joined to the first interconnection 114,and is constituted by the second conductive film 130.

Hereinafter, an example of a configuration of the joining structure 200,an example of a configuration of the light-emitting device 10, and anexample of a method of manufacturing the light-emitting device 10according to the this embodiment will be described in detail.

First, the example of the configuration of the joining structure 200according to this embodiment will be described.

The joining structure 200 is a joining structure in which the firstconductive film 110 and the second conductive film 130 are joined toeach other. In this embodiment, the joining structure 200 is formed, forexample, on a substrate 100. In this case, the first conductive film 110and the second conductive film 130 are formed on the substrate 100.

For example, the joining structure 200 constitutes a light-emittingdevice that includes an organic EL element. For example, thelight-emitting device includes an organic EL element, a firstinterconnection that is electrically connected to an electrode thatconstitutes the organic EL element, and a lead-out interconnection thatis electrically connected to the first interconnection. At this time, anelectrical signal, which controls light-emission and non-light-emission,is supplied to the electrode that constitutes the organic EL elementfrom the outside through the lead-out interconnection and the firstinterconnection.

In this embodiment, the first conductive film. 110 in the joiningstructure 200 constitutes, for example, the first interconnection thatis connected to the electrode that constitutes the organic EL element.In addition, the second conductive film 130 in the joining structure 200constitutes, for example, a lead-out interconnection. In this case, thejoining structure 200 is formed between the first interconnection andthe lead-out interconnection.

The first conductive film 110 substantially includes a conductivematerial. Examples of the conductive material, which constitutes thefirst conductive film 110, include a transparent conductive material,and paste-like conductive materials such as silver. Among these, thetransparent conductive material is particularly preferable. In a casewhere the first conductive film 110 is constituted by the transparentconductive material, the first conductive film 110 becomes a conductivefilm having transparency.

In this embodiment, for example, the first conductive film 110 has ashape that extends in a direction parallel to a plane of the substrate100.

For example, the transparent conductive material includes an inorganicmaterial such as indium tin oxide (ITO) and indium zinc oxide (IZO), ora conductive polymer.

In a case where the transparent conductive material includes theconductive polymer, the first conductive film 110 can be formed by usinga coating method. In this case, in a process of forming the firstconductive film 110, it is possible to suppress a thermal load frombeing applied to other configurations such as the substrate 100.

In addition, in a case where the inorganic material is included as thetransparent conductive material, it is preferable that the firstconductive film 110 is a coating-type conductive film that is formedthrough application of a solution in which the inorganic material isdispersed in an organic solvent. Even in this case, the first conductivefilm 110 can be formed by using the coating method.

In this embodiment, examples of the conductive polymer, which isincluded in the transparent conductive material that constitutes thefirst conductive film 110, include a conductive polymer that includes an-conjugated conductive polymer and a polyanion. In this case, it ispossible to form the first conductive film 110 that is particularlyexcellent in conductivity, heat resistance, and flexibility.

Although not particularly limited, examples of the n-conjugatedconductive polymer that can be used include chain-line conductivepolymers such as polythiophenes, polypyrroles, polyindoles,polycarbazoles, polyanilines, polyacetylenes, polyfurans,polyparaphenylene vinylenes, polyazulenes, polyparaphenylenes,polyparaphenylene sulfides, polyisothianaphthenes, and polythiazyls. Thepolythiophenes or the polyanilines are preferable from the viewpoints ofconductivity, transparency, stability, and the like, andpolyethylenedioxythiophene is more preferable.

Examples of the polyanion, which can be used, include polyvinyl sulfonicacid, polystyrene sulfonic acid, polyallyl sulfonic acid, polyacrylicacid ethyl sulfonic acid, polyacrylic acid butyl sulfonic acid,poly-2-acrylamide-2-methylpropane sulfonic acid, polyisoprene sulfonicacid, polyvinyl carboxylic acid, polystyrene carboxylic acid, polyallylcarboxylic acid, polyacrylic carboxylic acid, polymethacrylic carboxylicacid, poly-2-acrylamide-2-methylpropane carboxylic acid, polyisoprenecarboxylic acid, and polyacrylic acid. The polyanions, which can be usedin this embodiment, may be homopolymers thereof, or copolymers of two ormore kinds thereof.

In a case where the conductive polymer is included as the transparentconductive material that constitutes the first conductive film 110, thetransparent conductive material may further contain a cross-linkingagent, a leveling agent, an anti-foaming agent, and the like.

The second conductive film 130 includes a metal material. Here, as themetal material that is included in the second conductive film 130, forexample, a metal material having electric resistance lower than that ofthe conductive material that constitutes the first conductive film 110is used. In this case, the first conductive film 110 and the secondconductive film 130 are constituted by materials different from eachother.

Examples of the metal material, which is included in the secondconductive film 130, include Ag, Al, Cr, Mo, Ni, Nb, Ti, W, Au, Pt, Cu,and Pd. The second conductive film 130 is, for example, a sintered bodythat is obtained through sintering of metal particles. Further, thesecond conductive film 130 may be formed by, for example, a sputteringmethod or a deposition method.

In this embodiment, the first conductive film 110 is formed in such amanner that one end of the first conductive film 110 overlaps a part ofthe second conductive film 130 when seen in a plan view. In addition,for example, the first conductive film 110 is formed to cover a part ofeach of an upper surface and a lateral surface of the second conductivefilm 130.

Apart of the second conductive film 130 comes into contact with thefirst conductive film 110. For example, the second conductive film 130has a contact surface 206 that comes into contact with the firstconductive film 110, and a non-contact surface 208 that does not comeinto contact with the first conductive film 110. The second conductivefilm 130 is joined to the first conductive film 110 on the contactsurface 206. In this embodiment, for example, the first conductive film110 covers a part of each of the upper surface and the lateral surfaceof the second conductive film 130. In this case, the second conductivefilm 130 has the contact surface 206 at a part of each of an uppersurface and a lateral surface, and the non-contact surface 208 at otherportions.

The plurality of concave portions 204 are provided in the contactsurface 206 of the second conductive film 130 which comes into contactwith the first conductive film 110. For example, the contact surface 206becomes a concavo-convex surface provided with a concave portion 204 anda convex portion 202. At this time, for example, a part of the firstconductive film 110 is inside the concave portion 204 that is providedin the contact surface 206.

Further, a surface profiles at a contact surface and a non-contactsurface of a lead-out interconnection 134 can be observed by using aprobe type step meter, SEM, AFM, and the like.

In this embodiment, the plurality of concave portions 204 are providedin the contact surface 206 of the second conductive film 130 which comesinto contact with the first conductive film 110. According to this, itis possible to increase a contact area between the second conductivefilm 130 and the first conductive film 110. According to this, it ispossible to increase adhesive strength between the second conductivefilm 130 and the first conductive film 110. In this case, it is alsopossible to improve heat resistance against heat cycles and electricalreliability. In this manner, it is possible to realize an improvement inthe connection reliability between the first conductive film 110 and thesecond conductive film 130.

For example, an arithmetic average roughness Ra at the concavo-convexsurface of the second conductive film 130, which is formed in aconcavo-convex shape, is 0.1 μm or greater. The concavo-convex surfaceincludes the contact surface 206 of the second conductive film 130 whichcomes into contact with the first conductive film 110. When Ra of theconcavo-convex surface is set to 0.1 μm or greater, it is possible tosufficiently increase the adhesive strength between the secondconductive film 130 and the first conductive film 110. For example, thethickness of the second conductive film 130 is 0.5 μm to 5 μm. At thistime, it is preferable that the arithmetic average roughness Ra at theconcavo-convex surface of the second conductive film 130 is 10% to 80%with respect to the thickness of the second conductive film 130. When Raof the concavo-convex surface is set to 10% or greater with respect tothe thickness of the second conductive film 130, it is possible tosufficiently increase the adhesive strength between the first conductivefilm 110 and the second conductive film 130. In addition, when Ra of theconcavo-convex surface is set to 80% or less of the thickness of thesecond conductive film 130, it is possible to suppress an increaseinterconnection resistance in the second conductive film 130.

Here, the arithmetic average roughness Ra represents an average of anabsolute value of the height of a contour curve in a reference lengthwhich is defined in JIS B 0601. The same shall apply hereinafter in thisspecification. In addition, the arithmetic average roughness Ra on thecontact surface 206 and the non-contact surface 208 can be measured byusing a probe-type step meter, SEM, AFM, and the like.

In this embodiment, for example, the contact surface 206 has a surfaceroughness greater than a surface roughness of the non-contact surface208 of the second conductive film 130 which does not come into contactwith the first conductive film 110. In this case, it is possible tosuppress the surface roughness at the non-contact surface 208. Accordingto this, it is possible to suppress an increase in a resistance value atthe second conductive film 130 due to concavity and convexity on thesurface of the second conductive film 130. Further, the surfaceroughness of the contact surface 206 and the surface roughness of thenon-contact surface 208 can be compared with each other by using, forexample, an arithmetic average roughness Ra. Here, the arithmeticaverage roughness Ra on the contact surface 206 is set to Ra₁, and thearithmetic average roughness Ra at the non-contact surface 208 is set toRa₂. At this time, for example, Ra₁ is greater than Ra₂. According tothis, it is possible to significantly improve the adhesive strengthbetween the first conductive film 110 and the second conductive film 130while suppressing an increase in the resistance value of the secondconductive film 130.

Further, here, for example, the arithmetic average roughnesses Ra₁ andRa₂ can be obtained with Ra₁ as the arithmetic average roughness in ascanning range of 100 μm from a boundary between the contact surface 206and the non-contact surface 208 toward the contact surface 206 side, andRa₂ as the arithmetic average roughness in a scanning range of 100 μmfrom the boundary toward the non-contact surface 208 side.

In addition, the surface roughness of the contact surface 206 may be thesame as the surface roughness of the non-contact surface 208. Inaddition, the surface roughness of the non-contact surface 208 may begreater than that of the contact surface 206.

The second conductive film 130 may have a porous structure having a void210 formed therein, at a portion that overlaps the first conductive film110. In this case, a residual stress after generation of a thermalstress in the second conductive film 130 can be absorbed throughdeformation of the shape of the void 210. According to this, it ispossible to suppress peeling-off at the interface between the secondconductive film 130 and the first conductive film 110 due to theresidual stress.

For example, a plurality of the voids 210 are provided inside the secondconductive film 130. In addition, for example, the second conductivefilm 130 is a porous film having a porous structure at the entiretythereof. Further, the second conductive film 130 may be formed in such amanner that only a portion overlapping the first conductive film 110 isa porous structure when seen in a plan view.

In this embodiment, in a cross-sectional shape of at least a part of theplurality of concave portions 204 which are provided in the contactsurface 206, for example, at least a part between an opening end and abottom portion of the concave portion 204 has a cross-sectional widththat is greater than a cross-sectional width of the opening end. In thiscase, it is possible to increase a contact area between the secondconductive film 130 and the first conductive film 110 in the concaveportions 204. According to this, it is possible to increase the adhesivestrength between the second conductive film 130 and the first conductivefilm 110. In addition, a part of the first conductive film 110 insidethe concave portions 204 is prevented from falling out to the outside ofthe concave portions 204. According to this, it is possible to suppresspeeling-off of the first conductive film 110 from the second conductivefilm 130.

Further, the cross-sectional shape of the concave portions 204 can beobserved by using SEM and the like.

FIG. 6 illustrates an example in which the concave portion 204 is alsoformed in the non-contact surface 208 of the second conductive film 130,which does not come into contact with the first conductive film 110, inaddition to the contact surface 206 of the second conductive film 130which comes into contact with the first conductive film 110. Here, forexample, a plurality of the concave portions 204 are provided at a partof the non-contact surface 208 which is continuous to the contactsurface 206. In this case, the contact surface 206 and a part of thenon-contact surface 208 which is continuous to the contact surface 206are formed in a concavo-convex shape.

In an example illustrated in FIG. 6, the surface of the secondconductive film 130 except for at least a lower surface is formed in aconcavo-convex shape. In this case, for example, concavity and convexityare provided at the entirety of the upper surface and the lateralsurface in the second conductive film 130. Further, the lower surface ofthe second conductive film 130 may be flat or may be formed in aconcavo-convex shape.

FIG. 7 also illustrates an example in which the concave portion 204 isformed in the contact surface 206 and the non-contact surface 208 of thesecond conductive film 130. Here, an example, in which the void 210 isformed inside a portion of the second conductive film 130 which overlapsthe first conductive film 110, is illustrated.

In the example illustrated in FIG. 7, the second conductive film 130 isa porous film having a porous structure in which a plurality of voids210 are provided over the entirety of the second conductive film 130. Inaddition, the surface of the second conductive film 130 other than thelower surface is formed in a concavo-convex shape. Further, the lowersurface of the second conductive film 130 may be flat or may be formedin a concavo-convex shape.

FIG. 8 illustrates an example in which the concave portion 204 is notformed in the non-contact surface 208 of the second conductive film 130which does not come into contact with the first conductive film 110. Inthis case, only the contact surface 206 is formed in a concavo-convexshape. In addition, the non-contact surface 208 becomes a flat surface.

In the example illustrated in FIG. 8, a part of each of the uppersurface and the lateral surface of the second conductive film 130 isformed in a concave-convex shape. At this time, for example, in theupper surface of the second conductive film 130, a part continuous tothe lateral surface that faces the first conductive film 110 is formedin a concavo-convex shape.

In this embodiment, for example, the joining structure 200, in which thefirst conductive film 110 and the second conductive film 130 are joinedto each other, is formed as follows.

First, the second conductive film 130 is formed on the substrate 100.The second conductive film 130 is formed by using, for example, acoating method, a sputtering method, or a deposition method. The coatingmethod that is used in the process is not particularly limited andexamples thereof include an ink-jet method, a screen printing method, aspray coating method, and a dispenser coating method.

In a case of forming the second conductive film 130 by the coatingmethod, for example, the second conductive film 130 is formed by dryinga coating film that is formed by applying a coating solution containingmetal particles on the substrate 100. As the coating solution, forexample, a coating solution that includes a binder resin and an organicsolvent is used. As the binder resin, for example, a cellulose-basedresin, an epoxy-based resin, or an acryl-based resin can be used. As theorganic solvent, for example, a hydrocarbon-based solvent, or analcohol-based solvent can be used. In addition, examples of the metalparticles, which are contained in the coating solution, include Ag, Al,Cr, Mo, Ni, Nb, Ti, W, Au, Pt, Cu, or Pd.

Further, in a case of forming the second conductive film 130 by thecoating method, it is preferable that after forming the coating film byapplying the coating solution containing the metal particles on thesubstrate 100, a heat treatment is carried out with respect to thecoating film, thereby sintering the metal particles in the coating film.

Next, a roughening treatment is carried out with respect to the surfaceof the second conductive film 130. In this embodiment, the rougheningtreatment is carried out with respect to at least a portion of thesecond conductive film 130 which becomes the contact surface 206.According to this, the plurality of concave portions 204 are formed inthe portion of the second conductive film 130 which becomes the contactsurface 206.

In this embodiment, for example, an etching treatment is carried outwith respect to the surface of the second conductive film 130, therebycarrying out the roughening treatment. For example, the etchingtreatment is carried out by spraying hydrogen peroxide-sulfuricacid-based etching solution onto the surface of the second conductivefilm 130 for 10 seconds to 10 minutes. In addition, for example, theroughening treatment may be carried out by forming protrusions on thesurface of the second conductive film 130 by using a printing methodwith an ink-jet printer (IJP), a vacuum deposition method, and the likefor roughening of the surface of the second conductive film 130.

At this time, it is possible to control a cross-sectional shape or thesurface roughness of the concave portions 204 by appropriately selectingtreatment conditions such as an etchant and an etching time, or amaterial that constitutes the protrusions which are formed on thesurface of the second conductive film 130 during the etching treatment.According to this, a cross-sectional shape of at least a part of theplurality of concave portions 204 provided at a portion of the secondconductive film 130 which becomes the contact surface 206 may be set asa shape in which at least a part between the opening end and the bottomof the concave portions 204 has a cross-sectional width greater than across-sectional width of the opening end. In addition, it is possible tocontrol each of the surface roughness of the contact surface 206 and thesurface roughness of the non-contact surface 208.

Further, in a case where the second conductive film 130 is formed by thecoating method, it is assumed that the surface profile of the secondconductive film 130 is obtained due to deformation during evaporation ofa solvent in a drying process. According to this, it is possible to formthe concave portions 204 having a desired cross-sectional shape in thesurface of the second conductive film 130 by appropriately selecting theorganic solvent or the binder resin in the coating solution, asolid-content in the coating solution, drying conditions such as atemperature and time, and the like. In addition, it is possible to formthe second conductive film 130 which is formed as a porousinterconnection by appropriately selecting a particle size of the metalparticles in the coating solution, the organic solvent or the binderresin which is included in the coating solution, a sinteringtemperature, and the like.

According to this, in a case where the second conductive film 130 isformed by the coating method, the above-described roughening treatmentwith respect to the surface of the second conductive film 130 may not becarried out.

Next, the first conductive film 110 is formed on the substrate 100. Forexample, the first conductive film 110 is formed by applying an coatingsolution that contains the transparent conductive material onto thesubstrate 100, and drying the coating solution. For example, the firstconductive film 110 is formed to cover apart of the second conductivefilm 130. Here, the first conductive film 110 is formed to come intocontact with a portion of the second conductive film 130 in which theconcave portions 204 are formed. Although not particularly limited, thecoating solution that contains the transparent conductive material isapplied onto the substrate 100 by using an ink-jet method, a screenprinting method, a letterpress printing method, a gravure printingmethod, die coating, spin coating, or spraying. For example, the coatingsolution that contains the transparent conductive material, which isused in the process of forming the first conductive film 110, includesan organic solvent, water, or the like in addition to theabove-described transparent conductive material. As the organic solvent,for example, an alcohol-based solvent can be used. Further, the firstconductive film 110 may be formed by applying a paste-like conductivematerial such as silver onto the substrate 100 and the drying theconductive material.

Next, an example of a configuration of the light-emitting device 10 willbe described.

FIG. 1 illustrates a case in which the light-emitting device 10 is adisplay.

Further, the light-emitting device 10 may be an illuminating device. Ina case where the light-emitting device 10 is the illuminating device,for example, the light-emitting device 10 has a configuration in which aplurality of linear organic layers 140 having light emission colorsdifferent from each other are repetitively arranged. According to this,an illuminating device, which is excellent in color renderingproperties, is realized. In addition, the light-emitting device 10,which is the illuminating device, may include a sheet-shaped organiclayer 140.

For example, the substrate 100 is a transparent substrate. In thisembodiment, the substrate 100 may be configured as a glass substrate.According to this, it is possible to manufacture the light-emittingdevice 10 excellent in heat resistance and the like at a low cost.

The substrate 100 may be a film-shaped substrate that is constituted bya resin material. In this case, particularly, it is possible to realizea display with high flexibility. Examples of the resin material thatconstitutes the film-shaped substrate include polyethyleneterephthalate, polyethylene naphthalate, and polycarbonate. In addition,the substrate 100 may be a combination of glass and a resin material.According to this embodiment, even when the optical device(light-emitting device 10) has flexibility, connection reliability inthe joining structure 200 constituted by the first conductive film 110and the second conductive film 130 is high, and thus an effect ofreducing power consumption is high.

For example, the light-emitting device 10, which is a display, includesa plurality of the organic EL elements 20 which are arranged in an arrayshape on the substrate 100. Each of the organic EL elements 20 includesthe first electrode 112 that is provided on the substrate 100, theorganic layer 140 that is provided on the first electrode 112, and thesecond electrode 152 that is provided on the organic layer 140. At thistime, the organic layer 140 is disposed between the first electrode 112and the second electrode 152.

In this embodiment, for example, a plurality of the first electrodes 112which extend in a Y-direction in the drawing, and a plurality of thesecond electrodes 152 which extend in an X-direction in the drawing areprovided on the substrate 100. In addition, the organic EL element 20 isformed at each portion in which each of the first electrodes 112 andeach of the second electrodes 152 overlap each other when seen in a planview. According to this, a plurality of the organic EL elements 20,which are arranged in an array shape, are formed on the substrate 100.

The first electrode 112 becomes, for example, a positive electrode ofthe organic EL element. In this case, for example, the first electrode112 becomes a transparent electrode that is transparent or translucentwith respect to a wavelength of light emitted from a light-emittinglayer 144 of the organic layer 140 to be described later. In addition,for example, on the substrate 100 and within a pixel region 300, thefirst electrode 112 is provided to extend in a linear shape in theY-direction in the drawing. In addition, for example, the plurality offirst electrodes 112, which are spaced away from each other, arearranged on the substrate 100 in a direction (X-direction in thedrawing) perpendicular to the extension direction of the firstelectrodes 112. At this time, for example, the plurality of firstelectrodes 112 are spaced away from each other. Further, the pixelregion 300 is a region including the plurality of organic EL elements20. In an example illustrated in FIG. 4, a region surrounded by aone-dot chain line corresponds to the pixel region 300.

In this embodiment, for example, the first electrode 112 is constitutedby a transparent conductive material. As the transparent conductivematerial that constitutes the first electrode 112, for example, atransparent conductive material, which is the same as the transparentconductive material that constitutes the first conductive film 110, canbe used. According to this, the first electrode 112 can havetransparency.

For example, the first interconnection 114 is provided on the substrate100. In this embodiment, a case where the first interconnection 114 iselectrically connected to the first electrode 112 is exemplified. Atthis time, a plurality of the first interconnections 114, which arerespectively connected to different ones of the first electrodes 112,are provided on the substrate 100. According to this, each of theplurality of first electrodes 112 in this embodiment is connected to thelead-out interconnection 134 through each of the first interconnections114.

In this embodiment, the first interconnection 114 is constituted by thefirst conductive film 110 that is constituted by a conductive material.In a case where the first conductive film 110 is constituted by thetransparent conductive material, the first interconnection 114 that isconstituted by the first conductive film 110 can have transparency.

In this embodiment, for example, the first electrode 112 and the firstinterconnection 114 are integrally provided on the substrate 100. Inthis case, for example, the first interconnection 114 and the firstelectrode 112 are constituted by the first conductive film 110. At thistime, a portion of the first conductive film 110, which is located inthe pixel region 300 including the plurality of organic EL elements 20,becomes the first electrode 112. In addition, a portion of the firstconductive film 110, which is located outside the pixel region 300,becomes the first interconnection 114. The first electrode 112 isconnected to the lead-out interconnection 134 through the firstinterconnection 114.

In the example illustrated in FIG. 4, a plurality of first conductivefilms 110, which extend in the Y-direction in the drawing, are providedon the substrate 100. The plurality of first conductive films 110 arearranged in the X-direction in the drawing so as to be spaced away fromeach other. In addition, a portion of the first conductive film 110,which is located further on an end side that is connected to thelead-out interconnection 134 than the pixel region 300 indicated by theone-dot chain line, becomes the first interconnection 114.

The lead-out interconnection 134 is provided on the substrate 100.

In this embodiment, a case where the lead-out interconnection 134 andthe first interconnection 114 are connected to each other isexemplified. A plurality of the lead-out interconnections 134, which arearranged in the X-direction in the drawing and are spaced away from eachother, are provided on the substrate 100. Each of the lead-outinterconnections 134 is connected to each of the first interconnections114. According to this, each of the plurality of first interconnections114 is connected to an external side through each of the lead-outinterconnections 134. A signal for light-emission or non-light-emissionis supplied to the organic EL element 20 through the firstinterconnection 114 and the lead-out interconnection 134.

In this embodiment, the lead-out interconnection 134 is constituted bythe second conductive film 130 that is constituted by a metal material.According to this, in a case where the lead-out interconnection 134 andthe first interconnection 114 are connected to each other, the firstinterconnection 114 that is constituted by the first conductive film 110and the lead-out interconnection 134 that is constituted by the secondconductive film 130 are joined to each other, thereby forming thejoining structure 200. In the example illustrated in FIG. 4, the joiningstructure 200 is formed at a portion that is surrounded by a brokenline.

The first interconnection 114 is connected to the lead-outinterconnection 134 at one end. At this time, for example, the firstinterconnection 114 and the lead-out interconnection 134 are joined toeach other at the one end, thereby forming the joining structure 200.The first interconnection 114 extends in a first direction when seenfrom the lead-out interconnection 134. Further, the first direction inthis embodiment indicates, for example, the Y-direction in the drawing.

In this embodiment, the first interconnection 114 is formed in such amanner that one end of the first interconnection 114 overlaps apart ofthe lead-out interconnection 134. In addition, for example, the firstinterconnection 114 is formed to cover a part of each of the uppersurface and the lateral surface of the lead-out interconnection 134.

FIG. 4 illustrates a case where only an end of the lead-outinterconnection 134 on a pixel region 300 side overlaps the firstinterconnection 114 when seen in a plan view. In this case, the end ofthe lead-out interconnection 134 on the pixel region 300 side is coveredwith the first interconnection 114 and the other portion is exposedwithout being covered with the first interconnection 114. In thisembodiment, the lead-out interconnection 134 is covered with the firstinterconnection 114, for example, at a part of the upper surface, an endsurface that faces the pixel region 300, and a part of two lateralsurfaces which are adjacent to the end surface.

A part of the lead-out interconnection 134 comes into contact with thefirst interconnection 114. According to this, for example, the lead-outinterconnection 134, which is constituted by the second conductive film130, has the contact surface 206 that comes into contact with the firstinterconnection 114 that is constituted by the first conductive film110, and the non-contact surface 208 that does not come into contactwith the first interconnection 114 that is constituted by the firstconductive film 110. In this embodiment, for example, the firstinterconnection 114 covers a part of each of the upper surface and thelateral surface of the lead-out interconnection 134. In this case, thelead-out interconnection 134 has the contact surface 206 at a part ofeach of the upper surface and the lateral surface, and the non-contactsurface 208 at other portions.

The first interconnection 114 is constituted by the first conductivefilm 110. The lead-out interconnection 134 is constituted by the secondconductive film 130. According to this, the plurality of concaveportions 204 are provided in the contact surface 206 of the lead-outinterconnection 134 which comes into contact with the firstinterconnection 114.

In this embodiment, the lead-out interconnection 134 has the contactsurface 206 at a part of each of the upper surface and the lateralsurface thereof. According to this, the plurality of concave portions204 are provided in a part of the upper surface and the lateral surfaceof the lead-out interconnection 134. At this time, the concave portions204 may be provided at the entirety of the upper surface and the lateralsurface of the lead-out interconnection 134.

For example, the insulating layer 120 is provided on the substrate 100to cover the first electrode 112. In this embodiment, the insulatinglayer 120 is provided to cover, for example, a part of each of the firstelectrode 112, the first interconnection 114, and a lead-outinterconnection 164 to be described later.

The insulating layer 120 is a photo-sensitive resin such as apolyimide-based resin, and is formed in a desired pattern throughexposure and development. The insulating layer 120 may be constituted bya resin material other than the polyimide-based resin, and may be anepoxy-based resin or an acryl-based resin.

The insulating layer 120 is provided with, for example, a plurality offirst openings 122. As illustrated in FIG. 5, the first openings 122 areformed to constitute, for example, a matrix.

In this embodiment, the plurality of first openings 122 are formed to belocated on the first electrode 112. On each of the first electrodes 112which extend in the Y-direction in the drawing, for example, theplurality of first openings 122 are arranged in the Y-direction atpredetermined intervals. In addition, for example, the plurality offirst openings 122 are provided at a position that overlaps a secondelectrode 152 that extends in a direction (X-direction in the drawing)orthogonal to the first electrode 112. According to this, the pluralityof first openings 122 are arranged to constitute a matrix.

For example, a plurality of second openings 124 are provided in theinsulating layer 120.

As illustrated in FIG. 5, for example, the second openings 124 areprovided to be located on the lead-out interconnection 164. Theplurality of second openings 124 are arranged along one side of a matrixconstituted by the first openings 122. When seen in a direction (forexample, the Y-direction in the drawing) along the one side, the secondopenings 124 are disposed with the same interval as the first openings122.

For example, a partition wall 170 is provided on the insulating layer120.

As illustrated in FIG. 1, the partition wall 170 is provided to extendin the X-direction in the drawing. That is, the partition wall 170 isformed along an extension direction of the second electrode 152. Inaddition, a plurality of the partition walls 170 are provided to bearranged in the Y-direction in the drawing.

For example, the partition wall 170 is a photo-sensitive resin such as apolyimide-based resin, and is formed in a desired pattern throughexposure and development. Further, the partition wall 170 may beconstituted by a resin material other than the polyimide-based resin,and may be an epoxy-based resin or an acryl-based resin.

For example, a cross-section of the partition wall 170 has a shape(inverted trapezoidal shape) in which an upper side and a lower side ofa trapezoid are inverted from each other. That is, a width of the uppersurface of the partition wall 170 is greater than, for example, a widthof a bottom surface of the partition wall 170. In this case, even whencollectively forming the plurality of second electrodes 152 by asputtering method, a deposition method, and the like, it is possible toseparate the plurality of second electrodes 152, each being locatedbetween adjacent partition walls 170. Accordingly, it is possible toeasily form the second electrodes 152.

Further, a planar shape of the partition wall 170 is not limited to ashape illustrated in FIG. 1. Accordingly, when changing the planar shapeof the partition wall 170, it is possible to freely change a planarpattern of the plurality of second electrodes 152 which are separatedfrom each other by the partition wall 170.

As illustrated in FIG. 2, for example, the organic layer 140 is formedin the first openings 122.

In this embodiment, for example, the organic layer 140 is constituted bya stacked body in which a hole injection layer 142, a light-emittinglayer 144, and an electron injection layer 146 are sequentially stacked.At this time, the hole injection layer 142 comes into contact with thefirst electrode 112, and the electron injection layer 146 comes intocontact with the second electrode 152. According to this, the organiclayer 140 is interposed between the first electrode 112 and the secondelectrode 152.

Further, a hole transport layer may be formed between the hole injectionlayer 142 and the light-emitting layer 144, and an electron transportlayer may be formed between the light-emitting layer 144 and theelectron injection layer 146. In addition, the organic layer 140 may notbe provided with the hole injection layer 142.

In this embodiment, for example, the partition wall 170 is provided onthe insulating layer 120. In this case, as illustrated in FIG. 2, withregard to the organic layer 140 that is provided in each of a pluralityof regions interposed between adjacent partition walls 170, the organiclayers 140 are separated from each other in the Y-direction in thedrawing. Further, for example, a stacked film, which is constituted bythe same material as in the organic layer 140, is formed on thepartition wall 170.

On the other hand, as illustrated in FIG. 3, the respective layers,which constitute the organic layer 140, are provided to be continuousover the first openings 122 adjacent to each other in the X-direction inthe drawing in which the partition wall 170 extends.

The second electrode 152 is provided on the organic layer 140. Accordingto this, at least a part of the organic layer 140 is disposed betweenthe first electrode 112 and the second electrode 152.

In this embodiment, for example, the second electrode 152 becomes anegative electrode of the organic EL element. For example, the secondelectrode 152 is provided to extend in a linear shape in the X-directionin the drawing. In addition, for example, a plurality of the secondelectrodes 152, which are spaced away from each other, are arranged onthe substrate 100 in a direction (Y-direction in the drawing)perpendicular to the extension direction of the second electrodes 152.

For example, the second electrode 152 is constituted by a metal materialsuch as tin, magnesium, indium, calcium, aluminum, silver, and alloysthereof. These materials may be used alone or in an arbitrarycombination of two or more kinds thereof. Further, in a case where thesecond electrode 152 is a negative electrode, it is preferable that thesecond electrode 152 is constituted by a conductive material having awork function that is smaller than that of the first electrode 112 thatis a positive electrode.

A second interconnection 154 is provided on the substrate 100.

The second interconnection 154 is connected to either the firstelectrode 112 or the second electrode 152 which is not connected to thefirst interconnection 114. According to this, either the first electrode112 or the second electrode 152, which is connected to the secondinterconnection 154, is connected to the outside through the secondinterconnection 154.

In this embodiment, a case where the second interconnection 154 isprovided on the organic layer 140 and is connected to the secondelectrode 152 is exemplified. At this time, a plurality of the secondinterconnections 154, which are respectively connected to different onesof the second electrodes 152, are provided on the organic layer 140.According to this, each of the plurality of second electrodes 152 inthis embodiment is connected to the outside through each of the secondinterconnections 154. Further, for example, a part of the secondinterconnection 154 is embedded in the second opening 124, and isconnected to the lead-out interconnection 164 to be described later.

For example, the second interconnection 154 is constituted by a metalmaterial. As the metal material that constitutes the secondinterconnection 154, for example, the same metal material as in thesecond electrode 152 can be used.

In this embodiment, for example, the second electrode 152 and the secondinterconnection 154 are integrally provided on the organic layer 140,and constitute a conductive film 150. In this case, a portion of theconductive film 150, which is located in the pixel region 300 includingthe plurality of organic EL elements 20, becomes the second electrode152. In addition, a portion of the conductive film 150, which is locatedoutside the pixel region 300, becomes the second interconnection 154.For example, the second electrode 152 is connected to the lead-outinterconnection 164 through the second interconnection 154. Further, inan example illustrated in FIG. 1, a region surrounded by a one-dot chainline corresponds to the pixel region 300.

In the example illustrated in FIG. 1, a plurality of the conductivefilms 150, which extend in the X-direction in the drawing, are providedon the organic layer 140. In addition, the plurality of conductive films150 are arranged in the Y-direction in the drawing so as to be spacedaway from each other. In addition, a portion of each of the conductivefilms 150, which is located further on an end side that is connected tothe lead-out interconnection 164 than the pixel region 300, becomes thesecond interconnection 154.

For example, the plurality of conductive films 150 are collectivelyformed on the organic layer 140 by using a sputtering method, adeposition method, and the like. Even in this case, in this embodiment,the partition wall 170 is formed on the insulating layer 120.Accordingly, with regard to the conductive films 150 which are providedin a plurality of regions interposed between adjacent partition walls170, the conductive films 150 are separated from each other in theY-direction in the drawing.

According to this, it is possible to form the plurality of conductivefilms 150 which are arranged in the Y-direction in the drawing to bespaced away from each other and extend in the X-direction in thedrawing. At this time, a film that is constituted by the same materialas in the conductive film 150 is formed on each of the partition walls170.

For example, the lead-out interconnection 164 is provided on thesubstrate 100. The second interconnection 154 is connected to theoutside through the lead-out interconnection 164. According to this, thesecond electrode 152 is connected to the outside through the secondinterconnection 154 and the lead-out interconnection 164, and a signalis supplied thereto.

For example, the lead-out interconnection 164 is constituted by a metalmaterial. As the metal material that constitutes the lead-outinterconnection 164, for example, the same metal material as in thelead-out interconnection 134 can be used. In this case, the lead-outinterconnection 164 can be formed simultaneously with the lead-outinterconnection 134. According to this, it is possible to suppress anincrease in the number of manufacturing processes of the light-emittingdevice 10. Generally, an end of the lead-out interconnection (134 or164) forms a terminal portion of the light-emitting device 10. Theterminal portion is electrically connected to an external circuit. Ananisotropic conductive film (ACF) or a bonding wire is used forconnection between the terminal portion and the outer side.Particularly, in the optical device (light-emitting device 10) using thebonding wire, even in a case where the optical device has an irregularor circular shape, in addition to a rectangular shape, connectionreliability in the joining structure 200 that is constituted by thefirst conductive film 110 and the second conductive film 130 is high,and thus an effect of reducing power consumption is high.

Next, description will be give of an example of a method ofmanufacturing the light-emitting device 10.

First, the lead-out interconnection 134 is formed on the substrate 100.For example, the lead-out interconnection 134 is formed on the substrate100 by using a coating method, a sputtering method, or a depositionmethod. Further, in this embodiment, the lead-out interconnection 134 isconstituted by the second conductive film 130. According to this, forexample, the lead-out interconnection 134 is formed by using a method offorming the above-described second conductive film 130 and a materialthat constitutes the second conductive film 130. In addition, aroughening treatment may be carried out with respect to the surface ofthe lead-out interconnection 134 in the same manner as in theabove-described roughening treatment with respect to the surface of thesecond conductive film 130.

In addition, in this embodiment, for example, the lead-outinterconnection 164 is formed on the substrate 100 simultaneously withthe process of forming the lead-out interconnection 134. In this case,for example, the lead-out interconnection 164 is formed by the samemethod and the same material as in the lead-out interconnection 134.

Next, the first interconnection 114 is formed on the substrate 100. Forexample, the first interconnection 114 is formed by applying a coatingsolution that contains a transparent conductive material on thesubstrate 100, and by drying the coating solution. In addition, in thisembodiment, the first interconnection 114 is the first conductive film110. According to this, the first interconnection 114 is formed byusing, for example, a method of forming the above-described firstconductive film 110, and a material that constitutes the firstconductive film 110.

In the process of forming the first interconnection 114, for example,the first electrode 112 that is connected to the first interconnection114 is formed together with the first interconnection 114. In this case,for example, the first electrode 112 is formed integrally with the firstinterconnection 114 by the first conductive film 110.

Next, the heat treatment is carried out with respect to the firstinterconnection 114. According to this, the first interconnection 114 isdried. In a case where the transparent conductive material includes theconductive polymer, when the first interconnection 114 is dried, thecohesive force of the conductive polymer increases, and thus it ispossible to form the first interconnection 114 as a strong film. Inaddition, when the heat treatment is carried out with respect to thefirst interconnection 114, the first interconnection 114 is cured. Inaddition, in a case where the transparent conductive material thatconstitutes the first interconnection 114 includes a photo-sensitivematerial, the first interconnection 114 may be cured through UVirradiation.

A structure that is obtained at this stage is illustrated in FIG. 4.

Next, the insulating layer 120 is formed on the substrate 100, the firstelectrode 112, the first interconnection 114, and the lead-outinterconnection 164. The insulating layer 120 is patterned into apredetermined shape by using dry-etching, wet-etching, or the like.According to this, the plurality of first openings 122 and the pluralityof second openings 124 are formed in the insulating layer 120. At thistime, for example, the plurality of first openings 122 are formed insuch a manner that a part of the first electrode 112 is exposed fromeach of the first openings 122.

Next, the partition wall 170 is formed on the insulating layer 120. Thepartition wall 170 is obtained by patterning the insulating filmprovided on the insulating layer 120 into a predetermined shape by usingdry-etching, wet-etching, or the like. In a case where the partitionwall 170 is formed from a photo-sensitive resin, it is possible to allowthe partition wall 170 to have an inverted trapezoidal cross-sectionalshape by adjusting conditions during exposure and development. Astructure that is obtained at this stage is illustrated in FIG. 5.

Next, the hole injection layer 142, the light-emitting layer 144, andthe electron injection layer 146 are sequentially formed in the firstopenings 122. These may be formed by using, for example, a coatingmethod or a deposition method.

According to this, the organic layer 140 is formed.

Next, the conductive film 150, which constitutes the second electrode152 and the second interconnection 154, is formed on the organic layer140. At this time, for example, the conductive film 150 is formed insuch a manner that a part of the conductive film 150 is located insidethe second openings 124. The conductive film 150 is formed by using, forexample, a deposition method or a sputtering method.

According to this, the organic EL element 20, which is constituted bythe first electrode 112, the second electrode 152, and the organic layer140 that is interposed between the first electrode 112 and the secondelectrode 152, is formed on the substrate 100.

In this embodiment, for example, the light-emitting device 10 is formedas described above.

As described above, according to this embodiment, the plurality ofconcave portions 204 are provided in the contact surface 206 of thesecond conductive film 130 which comes into contact with the firstconductive film 110. According to this, it is possible to increase acontact area between the second conductive film 130 and the firstconductive film 110. According to this, it is possible to increase theadhesive strength between the second conductive film 130 and the firstconductive film 110. Accordingly, it is possible to realize animprovement in the connection reliability between the first conductivefilm 110 and the second conductive film 130.

In addition, it is possible to realize the light-emitting device 10including the first interconnection 114 that is connected to the firstelectrode 112 constituting the organic EL element 20 and is constitutedby the first conductive film 110, and the lead-out interconnection 134that is constituted by the second conductive film 130. According tothis, it is possible to improve connection reliability between the firstelectrode 112 and the lead-out interconnection 134. In addition, it ispossible to improve operation reliability of the light-emitting device10.

Second Embodiment

FIG. 9 is a plan view illustrating a light-emitting device 12 accordingto a second embodiment, and corresponds to FIG. 1 according to the firstembodiment. FIG. 10 is a cross-sectional view taken along line C-C inFIG. 9, and FIG. 11 is a cross-sectional view taken along line D-D inFIG. 9. FIG. 12 is a view illustrating a part of the light-emittingdevice 12 illustrated in FIG. 9. Particularly, FIG. 12 illustrates apositional relationship between the first conductive film 110 and thesecond conductive film 130.

In this embodiment, the first conductive film 110 of the joiningstructure 200 constitutes, for example, an electrode that constitutesthe organic EL element. The second conductive film 130 of the joiningstructure 200 constitutes, for example, a lead-out interconnection thatis electrically connected to an electrode that constitutes the organicEL element. In this case, the joining structure 200 is formed betweenthe electrode that constitutes the organic EL element and the lead-outinterconnection. In this case, the plurality of concave portions 204 areformed in the contact surface of the lead-out interconnection whichcomes into contact with an electrode that constitutes the organic ELelement.

The light-emitting device 12 according to this embodiment has the sameconfiguration as that of the light-emitting device 10 according to thefirst embodiment except for the configuration of a first electrode 112and a lead-out interconnection 134.

The light-emitting device 12 includes the joining structure 200. Thelight-emitting device 12 includes the organic EL element 20 and thelead-out interconnection 134. The organic EL element 20 includes thefirst electrode 112 that is constituted by the first conductive film110, the second electrode 152, and the organic layer 140 that isdisposed between the first electrode 112 and the second electrode 152.The lead-out interconnection 134 is joined to the first electrode 112,and is constituted by the second conductive film 130.

Hereinafter, description will be given of an example of a configurationof the light-emitting device 12.

In this embodiment, for example, the first electrode 112 is disposed onthe substrate 100 in a matrix shape in a pixel region 300. A pluralityof the first electrodes 112, which are disposed in a matrix shape, arespaced away from each other. Further, the pixel region 300 is a regionincluding a plurality of the organic EL elements 20. In an exampleillustrated in FIG. 9, a region surrounded by a one-dot chain linecorresponds to the pixel region 300.

The first electrode 112 is constituted by the first conductive film 110that is constituted by a conductive material. In a case where the firstconductive film 110 is constituted by a transparent conductive material,the first electrode 112, which is constituted by the first conductivefilm 110, can have transparency.

The light-emitting device 12 according to this embodiment is notprovided with the first interconnection 114 that constitutes thelight-emitting device 10 according to the first embodiment.

In this embodiment, a case where the lead-out interconnection 134 isconnected to the first electrode 112 is exemplified. The lead-outinterconnection 134 extends in the Y-direction in the drawing. Inaddition, a plurality of the lead-out interconnections 134, which arearranged in the X-direction in the drawing so as to be spaced away fromeach other, are provided on the substrate 100. Each of the lead-outinterconnection 134 is connected to each of a plurality of the firstelectrodes 112 which are arranged in the Y-direction. According to this,each of the plurality of first electrodes 112 is connected to theoutside through each of the lead-out interconnections 134. A signal forlight-emission or non-light-emission is supplied to the organic ELelement 20 through the lead-out interconnection 134.

In this embodiment, the lead-out interconnection 134 is constituted bythe second conductive film 130 that is constituted by a metal material.According to this, the first electrode 112 that is constituted by thefirst conductive film 110, and the lead-out interconnection 134 that isconstituted by the second conductive film 130 are joined to each other,thereby forming the joining structure 200. In an example illustrated inFIG. 12, the joining structure 200 is formed at a portion surrounded bya broken line.

The first electrode 112 is connected to the lead-out interconnection 134at one end thereof. At this time, for example, the first electrode 112is joined to the lead-out interconnection 134 at the one end thereof,thereby forming the joining structure 200. As illustrated in FIG. 11,for example, a portion of the lead-out interconnection 134, which isjoined to the first electrode 112, is located in a region in which theorganic EL element 20 is formed when seen in a plan view.

The first electrode 112 extends in a second direction when seen from thelead-out interconnection 134. Further, the second direction in thisembodiment represents, for example, the X-direction in the drawing. Theshape of the first electrode 112 is not particularly limited, and can beappropriately selected in combination with the design of the organic ELelement 20. Examples of the shape include a rectangular shape.

The lead-out interconnection 134 is provided in such a manner that atleast a part thereof overlaps the first electrode 112.

In an example illustrated in FIG. 12, the first electrode 112 is formedin such a manner that one end of the first electrode 112 overlaps a partof the lead-out interconnection 134. In this case, for example, thefirst electrode 112 is formed to cover a part of each of an uppersurface and a lateral surface of the lead-out interconnection 134. Atthis time, the lead-out interconnection 134 has the contact surface 206,which comes into contact with the first electrode 112, at a part of eachof the upper surface and the lateral surface. The plurality of concaveportions 204 are formed in the contact surface 206.

For example, the insulating layer 120 is formed to cover the lead-outinterconnection 134. In this embodiment, for example, the insulatinglayer 120 is provided to cover a part of each of the lead-outinterconnection 134 and a lead-out interconnection 164. In addition, asillustrated in FIG. 12, a plurality of first openings 122 are formed inthe insulating layer 120 so as to constitute, for example, a matrix.

In this embodiment, the first electrode 112 is formed in the firstopenings 122. According to this, a plurality of the first electrodes112, which are arranged in a matrix shape, are formed on the substrate100. In addition, as illustrated in FIGS. 10 and 11, the plurality offirst electrodes 112 are spaced away from each other by the insulatinglayer 120. For example, the first openings 122 are formed to overlap apart of the lead-out interconnection 134 when seen in a plan view. Inthis case, a part of the lead-out interconnection 134, which overlapsthe first openings 122 when seen in a plan view, is connected to thefirst electrode 112 that is formed in the first openings 122.

For example, the insulating layer 120 is constituted by the samematerial as in the first embodiment.

For example, the partition wall 170, the organic layer 140, the secondelectrode 152, the second interconnection 154, and the lead-outinterconnection 164 in this embodiment have the same configurations asthose in the first embodiment.

As described above, even in this embodiment, it is possible to improveconnection reliability between the first conductive film 110 and thesecond conductive film 130 similar to the first embodiment.

In addition, according to this embodiment, it is possible to realize thelight-emitting device 10 including the first electrode 112 that isconstituted by the first conductive film 110, and the lead-outinterconnection 134 that is constituted by the second conductive film130. According to this, it is possible to improve connection reliabilitybetween the first electrode 112 and the lead-out interconnection 134. Inaddition, it is possible to improve operation reliability of thelight-emitting device 12.

Third Embodiment

FIG. 13 is a plan view illustrating a configuration of a light-emittingdevice 10 according to a third embodiment. In this embodiment, forexample, the light-emitting device 10 is used as a light source of anilluminating device and the like. According to this, the light-emittingdevice 10 includes a terminal (end of the lead-out interconnection 134)that is connected to the first electrode 112, and a terminal (end of thelead-out interconnection 166) that is connected to the second electrode152. In addition, the light-emitting device 10 may include one piece ofthe organic EL element 20, but may include a plurality of the organic ELelements 20. In the latter case, a current simultaneously flows, andthus the plurality of organic EL element 20 are simultaneouslycontrolled. Further, in any case, the insulating layer 120 (notillustrated in the drawing) surrounds the organic EL element 20 so as todefine a region serving as the organic EL element 20.

A connection portion between the lead-out interconnection 134 and thefirst interconnection 114 is constituted by the joining structure 200illustrated in the first embodiment. In addition, the lead-outinterconnection 166 has the same configuration as that of the lead-outinterconnection 134. The lead-out interconnections 134 and 166 have aconfiguration in which a plurality of conductive layers are stacked. Inthis case, for example, the lead-out interconnections 134 and 166 have aconfiguration in which a first layer formed from Mo or a Mo alloy, asecond layer formed from Al or an Al alloy, and a third layer formedfrom Mo or a Mo alloy are stacked in this order.

Next, description will be given of a method of manufacturing thelight-emitting device 10 according to this embodiment. First, thelead-out interconnections 134 and 166 are formed on the substrate 100.The lead-out interconnections 134 and 166 are formed by using asputtering method or a deposition method. Subsequently, the firstconductive film 110 is formed. A method of forming the first conductivefilm 110 is the same as in the first embodiment. At this time, thejoining structure 200 is also formed. Subsequently, the insulating layer120, the organic layer 140, and the conductive film 150 are formed.

Further, the conductive film 150 may be formed by the same method as inthe first embodiment, or may be formed by the same method as for thefirst conductive film 110. In the latter case, a connection portionbetween the conductive film 150 and the lead-out interconnection 166also becomes the joining structure 200. In this case, the conductivefilm 150 corresponds to the first conductive film, and the lead-outinterconnection 166 corresponds to the second conductive film.

Even in this embodiment, since the joining structure 200 is formedbetween the lead-out interconnection 134 and the first interconnection114, connection reliability between the lead-out interconnection 134 andthe first interconnection 114 is improved. In addition, in a case offorming the conductive film 150 by the same method as in the firstconductive film 110, the connection portion between the conductive film150 and the lead-out interconnection 166 also becomes the joiningstructure 200, and thus connection reliability between the conductivefilm 150 and the lead-out interconnection 166 is also improved.

Fourth Embodiment

FIG. 14 is a cross-sectional view illustrating a configuration of anoptical device 11 according to a fourth embodiment. The optical device11 according to this embodiment is a liquid crystal device, and has aconfiguration in which a liquid crystal material 420 is interposedbetween a substrate 402 and a substrate 404.

Specifically, a first electrode 412 is formed on a surface of thesubstrate 402, which faces the substrate 404, and a second electrode 414is formed on a surface of the substrate 404 which faces the substrate402. Both the first electrode 412 and the second electrode 414 areformed from a transparent conductive material. In addition, a sealingmember 406 is provided between the substrate 402 and the substrate 404so as to surround a space that is filled with the liquid crystalmaterial 420. In other words, the substrate 402 and the substrate 404are fixed to each other by the sealing member 406. In addition, a spacesurrounded by the substrates 402 and 404, and the sealing member 406 isfilled with the liquid crystal material 420.

FIG. 15 is a plan view of the optical device 11. In FIG. 15, thesubstrate 404 and the second electrode 414 are not illustrated for easeof explanation.

As illustrated in FIG. 15, a plurality of the first electrodes 412extend on the substrate 402 in parallel with each other. Ends of theplurality of first electrodes 412 are located on an outer side of thesealing member 406, and are respectively connected to different ones ofterminals 432. A connection portion between each of the first electrodes412 and each of the terminals 432 is constituted by the joiningstructure 200.

Further, a plurality of the second electrodes 414 extend on thesubstrate 404 in a direction that intersects (for example, a directionthat is orthogonal to) the first electrodes 412. In addition, a terminalthat is connected to each of the second electrodes 414 is formed on thesubstrate 404. A connection portion between this terminal and the secondelectrode 414 is also constituted by the joining structure 200.

According to this embodiment, since the joining structure 200 is alsoformed between the first electrode 412 and the terminal 432, and betweenthe second electrode 414 and the terminal that is connected to thesecond electrode 414, connection reliability therebetween is improved.

Hereinafter, the embodiments will be described in detail with referenceto Examples. Further, the embodiments are not limited to the descriptionin Examples.

Example 1

First, an ink containing silver particles was applied onto a glasssubstrate in a linear shape by an ink-jet method, and then the ink thatwas applied was dried under conditions of 150° C. and 10 minutes,thereby forming the second conductive film. Here, an ink containingsilver particles was used, the ink including an acrylic resin as abinder component, an organic solvent, and silver particles contained inan amount of 70 parts by weight based on 100 parts by weight of thebinder component and had an average particle size of 100 μm.Subsequently, the second conductive film was subjected to a heattreatment under conditions of 400° C. and 10 minutes to 30 minutes,thereby sintering the second conductive film. Then, a coating solutioncontaining a transparent conductive material was applied in a linearshape and the coating solution was dried, thereby forming the firstconductive film. At this time, the coating solution containing atransparent conductive material was applied in such a manner that thefirst conductive film covered a part of the second conductive film whichhas been roughened. In addition, as the coating solution containing thetransparent conductive material, a solution, which was obtained bydispersing poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate(PEDOT-PSS, CLEVIOS PH510 (manufactured by Heraeus Holding)) in asolvent, was used. Subsequently, a heat treatment was carried out withrespect to the first conductive film under conditions of 120° C. and 2minutes, whereby the first conductive film was dried. According to this,a structure body including the first conductive film and the secondconductive film was prepared.

The structure body, which was obtained in this manner, was applied tothe light-emitting device according to the first embodiment.

In Example 1, a plurality of concave portions were observed on thecontact surface of the second conductive film which comes into contactwith the first conductive film. In addition, with regard to apart of theconcave portions, a cross-sectional shape, in which a part between theopening end to the bottom had a cross-sectional width greater than across-sectional width of the opening end, was observed. In addition, thesecond conductive film had a porous structure having avoid formedtherein, at a portion that overlapped the first conductive film.

In Example 1, when a current was allowed to flow between the firstconductive film and the second conductive film for a long period oftime, connection reliability between the first conductive film and thesecond conductive film was excellent.

Comparative Example 1

First, a transparent conductive film formed from ITO was formed on theglass substrate by a sputtering method. Subsequently, the transparentconductive film was patterned in a linear shape through dry-etching,thereby forming the first conductive film. Subsequently, a metal filmformed from silver was formed on the first conductive film by using thesputtering method. Subsequently, the metal film was patterned in alinear shape through dry-etching, thereby forming the second conductivefilm on the first conductive film. According to this, a structure bodyincluding the first conductive film and the second conductive film wasprepared.

In Comparative Example 1, the concave portions were not observed on thecontact surface of the second conductive film which comes into contactwith the first conductive film. In Comparative Example 1, when a currentwas allowed to flow between the first conductive film and the secondconductive film for a long period of time, the connection reliabilitybetween the first conductive film and the second conductive film wasinferior to the connection reliability in Example 1.

Hereinbefore, embodiments and Examples have been described withreference to the accompanying drawings. However, these are illustrativeonly, and various configurations other than embodiments and Examples canbe employed.

Priority is claimed on Japanese Patent Application No. 2013-076008,filed Apr. 1, 2013, the content of which is incorporated herein byreference.

1. An optical device, comprising: a joining structure in which a firstconductive film that is constituted by a conductive material and asecond conductive film that is constituted by a metal material arejoined to each other, wherein in the joining structure, a part of thesecond conductive film comes into contact with the first conductivefilm, and a plurality of concave portions are provided in a contactsurface of the second conductive film which comes into contact with thefirst conductive film.
 2. The optical device according to claim 1,wherein the contact surface has a surface roughness that is greater thana surface roughness of a non-contact surface of the second conductivefilm which does not come into contact with the first conductive film. 3.The optical device according to claim 1, wherein a part of the secondconductive film overlaps the first conductive film, and the secondconductive film has a porous structure having a void formed therein, ata portion that overlaps the first conductive film.
 4. The optical deviceaccording to claim 1, wherein, in a cross-sectional shape of at least apart of the plurality of concave portions which are provided in thecontact surface, at least a part between an opening end and a bottomportion of the concave portions has a cross-sectional width that isgreater than a cross-sectional width of the opening end.
 5. The opticaldevice according to claim 1, wherein the conductive material is atransparent conductive material including a conductive polymer.
 6. Theoptical device according to claim 1, wherein the first conductive filmis an electrode that constitutes an organic EL element, and the secondconductive film is an interconnection that is electrically connected tothe electrode.
 7. The optical device according to claim 1, wherein thefirst conductive film is a first interconnection that is connected to anelectrode that constitutes an organic EL element, and the secondconductive film is a lead-out interconnection that is electricallyconnected to the first interconnection.
 8. The optical device accordingto claim 1, further comprising: an organic EL element including a firstelectrode that is constituted by the first conductive film, a secondelectrode, and an organic layer that is disposed between the firstelectrode and the second electrode; and a lead-out interconnection thatis joined to the first electrode, and is constituted by the secondconductive film.
 9. The optical device according to claim 1, furthercomprising: an organic EL element including a first electrode, a secondelectrode, and an organic layer that is disposed between the firstelectrode and the second electrode; a first interconnection that iselectrically connected to the first electrode, and is constituted by thefirst conductive film; and a lead-out interconnection that is joined tothe first interconnection, and is constituted by the second conductivefilm.